1. Field of the Invention
This invention relates filling valve arrangements for container filling apparatus in which a pressurized liquid containing bowl is provided with multiple filling valves which are substantially self-contained and individually mounted on the bowl.
2. Description of the Prior Art
In traditional ball check mechanisms, as liquid hits the ball during the container filling cycle, the ball moves to a seated position at the end of the gas vent tube to effectively close the opening through which the gas is delivered into and vented from the container. In some instances the outflow of gas caused by the incoming liquid creates a venturi effect and occasionally the ball is sucked up prematurely, thus defeating the purpose for the valve. Normally the ball is gravity influenced to open the gas vent tube until it is lifted by the liquid admitted to the container.
There are a number of patents granted on container filling control valve arrangements in which a ball check has been incorporated. These included Meyer U.S. Pat. Nos. 3,067,785 of Dec. 11, 1962; Naecker 3,090,408 of May 21, 1963; and Breeback 3,192,966 of July 6, 1965. In addition there are a number of patents on the arrangement of the liquid flow passages and control thereover, such as Meyer, et al U.S. Pat. Nos. 2,467,684 of Apr. 19, 1949; Meyer 2,597,943 of May 27, 1952; and Rademacher 3,834,428 of Sept. 10, 1974.
Other prior art related to container filler mechanism with gas vent tubes include Sommers U.S. Pat. Nos. 2,847,043 of Aug. 12, 1958; Granier 3,018,804 of Jan. 30, 1962; and Granier 3,209,794 of Oct. 5, 1965. In these examples the gas vent tubes are not provided with liquid check valves as the emphasis appears to be placed on the operation of the counter-pressure valve for controlling the admission and shut-off of liquid flow into a container in association with valve operating mechanism disposed in the bowl holding the liquid and gas.
The foregoing known prior art present examples of filler apparatus having short gas vent tubes, operating mechanism located within the pressurized bowl for the liquid, and liquid flow passages which are prone to generate great turbulence during the liquid transfer under pressure. A further problem with the known prior art examples is the pressure loss associated with the form of the flow passages due to high friction, all of which significantly reduces the filling time. It is also a problem with known devices that a certain amount of liquid which enters the gas vent tube is blown out into the next container, and foaming results. While ball check elements are intended for preventing the entrance of liquid into the vent tubes while the gas is escaping, they do not achieve a smooth escape of the gas so that container filling time is slowed down, and there is a residue of liquid in the tube which, on the next filling cycle gets blown into the container, or it must be blown out which allows fine droplets of the liquid to penetrate the ambient areas.
Moreover, a ball type check valve presents a problem of adapting its weight to the desired valve. Balls are not easily made hollow to adjust weight, they cannot be formed with an open hole as the position of the hole cannot be controlled, and changing the ball size is not practical for weight selection as the means for caging the ball must also be changed to receive the ball. Changing materials also proves to be a problem because changing density solves only one problem and corrosion resistance from product and standard cleaning solutions presents another.